to last through the spring and summer and their still be some evidence of it next Christmas.

Lets start with a few assumptions.
1. Its going to be at sea level;
2. It will be a perfect cone shape;
3. It wont be compacted at all;
4. Say density of 10%; and
5. It would be located in Hyde Park.

Come then all you engineers / physicists / mathematicians lets have it.

According to my calculations it would need to be very big.

Trick question. 1 and 5 are mutually exclusive.

depends, are we assuming were going to have a normal british rainy summer, or some actual sun for once?

Not that i'd ever be able to work it out..

Trick question. 1 and 5 are mutually exclusive.

Ok, lets say the elevation of Hyde Park then – can't be much above see level?

Streetmap says 20m, so lets go with that.

depends, are we assuming were going to have a normal british rainy summer, or some actual sun for once?

Average temp and rainfall across the year – Say 100 year averages? Is that doable?

You need to also state whether or not it will get full sun

Back in 82 ish
We had a pile of snow that had been bull-dozed off the car park at work into a big pile one Feb morning – it lasted until June
It was about 12' high to start with & shaded from the sun

I've just input the data into my supercomputer 'deep thought' & it would need to be 42.
42 what, I have no idea.

I used to make big outdoor ice sculptures for music festivals and the like, sun was fine but rain would kill them.

Are you planning something like this?

Ok, full sun it is….and no its not on a conveyer belt 😆

There are a few snow patches in the highlands that sometimes make it right through the summer, they are sheltered from the wind and very big bodies of snow to start with, perhaps finding out their size would be a good start point then compare altitude and climate

http://www.edwardboyle.com/perennial_snow1.html

could it be carried by a baby robin?

Would have to be huge.

You only really get small patches in very sheltered spots in the Scottish hills by late summer – we are 600 miles further north and 1000m+ higher than London.

See http://en.wikipedia.org/wiki/Snow_patches_in_Scotland

Well, the Arctic Ocean melts every Summer, and glaciers, so it would have to be several hundred feet of ice.

Trick question. 1 and 5 are mutually exclusive.

Maybe he's planning on digging a big hole to get down to sea level. I suppose that might also help shelter the snow – though it would also tend to fill up with water which would tend to melt it.

My very careful calculations suggest the answer is somewhere between 2.137 and 1396.602

aracer, no marks if you don't show your workings 🙂

Glaciers don't melt each year, that's why they're glaciers.

Lets start piling up the snow so we can do an experiment then. But I reckon it will all melt before we manage to pile up enough.

I suggest we put all the snow in a giant wafer cone and charge people 50p to look at it. I'll start work on a lottery grant for it now

Andy Goldsworthy's mid-summer London snowballs didn't last very long

Right then. I did some maths.

Now I’m assuming a perfect cone equates to one with a diameter (2r) equal to the height. That gives us an external surface area of

SA = pi * r * (sqrt(2r^2+2r^2))
Volume = 1/3 * pi * r^2 * 2r

According to ‘the internet’ the amount of energy falling on one m sq of the earth per second is 364J. Which gives us 3.14E+7 J per day (364*60*60*24). There are 343 days to xmas so that gives us a total energy of 1.08E+10 J falling on our idealised non cloudy average square meter of earth. However, it’s actually only falling for half that time (approx) on account of night. So we divide by two. 5.39E+9 J per year per m2.

Now the amount of energy required to raise 1g of water by 1 degree is 4.18J. Which is 4.18E+6 J to raise a m3 by 1 degree.

Having done some graphs it appears that it’s not just a mater of the size but also how cold it is to start with. If it’s minus 20 to start with, then it’ll always melt within the time frame stated.

To cut a long story short, it would appear that 220m in radius or 440m in diameter is the magic number assuming -20 to start with and that at 0 degrees it’s all melted. Excel can be supplied upon request!

Obviously this leaves out the density stuff.

Update – I forgot that the density of ice is only 90% (ish) of that of water. Make that 200m in radius.

What's the effect of tramps and drunk stockbrokers weeing on the snow?

What's the effect of tramps and drunk stockbrokers weeing on the snow?

reduced property prices for houses with a view of the park

what about sublimation energy requirements, and the latent heat effects of melting…?
i guess one is assuming that the weight of the cone will not have an effect on the compression of the snow inside the cone?

Ewan – legendry!

Good try Ewan.

However, you have excluded the nights on the basis that they get no sunlight. However, the ambient temperature at night can be, and usually is, above freezing, so although the sunlight would not be supplying the energy required to melt the snow it would still be able to draw energy from the air around it, provided that air was at a greater temperature than the snow. Any cold nights would lead to more freezing of the snow, increasing it's density and prolonging it's life. However, the number of nights when the temperture does not fall below freezing is exceeded many-fold by the number of above-freezing nights.

Was it not discussed on here sometime ago that it is quicker to get to boiling point if you start with ice than water?

So if we started with a big cone of water then it wouldnt evaporate so fast but conversly would dramatically reduce the time it takes to run down the drain.

PS. this post has very little relevance to anything.

God i'm bored!

I'm (well once was) an engineer. Everything's a approximation to me 😀

Latent heat will probably be signifcant, i've avoided compression effects as i've assumed it's a solid (and thus imcompressible) block of ice. Also assumes it's a black body, which is fairly inaccurate!

There is a rule of thumb that it's one inch per degree above freezing per day (though this sounds a bit high for temperatures a bit above zero).

Taking the average temperature from teh met office at Greenwich, this would mean the pile woudl have to be 314ft high to survive to Christmas (not accounting for the fact that the temperature woudl be a bit cooler at the top than at Greenwich – or hyde Park level).

If teh rule was per degree Farenheit, it's about 565ft.

In bramar it would be 195ft and 4,000ft up in the cairngorms (1c per 100m rule) it's 45ft

Only thing to worry about in Aberdeen now though is the depth of rain!

John